Tweco 100 Ultra-Cut Plasma Cutting System with Automated Gas Control - Manual (Page 191)

ULTRA-CUT 100 XT
Manual 0-5303 APPENDIX A-67
253-258 Inverter Over Temperature.
Each inverter section (IS) contains one or more temperature sensors. If any of these detect an over temperature
condition it activates the signal “OVERTEMP_FLT going to the CCM over the inverter sections ribbon cable.
Inverters semiconductors (transistors and diodes) are liquid cooled. Anything that increases the coolant tem-
perature too high can cause overheating of the inverters. The inverters magnetics (transformer & inductors)
are air cooled by the same fan(s) that cool(s) the liquid.
Possible causes:
• Cooling fan(s) not operating.
• Disrupted air flow.
• Defective inverter module.
• Inverter Ribbon cable bad connection.
• Defective CCM.
Originally 100 and 200A units had 2 smaller fans while 300 & �00A used a single larger fan along with a larger
radiator. More recently, the single larger fan may be used in the 100 & 200A as well.
Troubleshooting:
1. Confirm that air is exhausting from both the top (top fan)and bottom (bottom fan of units with 2 fans) of the
opening in the right side panel. As the fan(s) are behind the radiator it’s hard to see them to confirm they
are turning but perhaps you can use an inspection mirror. Refer to section for code 403 for troubleshooting
defective fans.
!
WARNING!
Fan blades can be moving and accidental contact with a mirror or other inspection devise can cause personal injury
or damage to the machine.
2. Leaving the side panels and cover off, especially the left lower side or the top cover will reduce the air flow.
Also if the radiator fins become clogged with dust it will reduce air flow. Clean the radiator periodically by
blowing air into it to clear dirt from the fins.
259-264 Inverter Over Temperature due to high Ambient.
The CCM measures the ambient temperature where the cooling air enters the louvers on the left side of the
front panel. If an inverter goes over temperature and we have determined that the ambient exceeds �0 deg C
we will get one or more of the high ambient codes, 252-2��. The sensor, TS2, is a NTC (Negative Temperature
Coefficient) resistor whose resistance varies with temperature. It is mounted on the inside of the front panel
next to the louvers on the left. To access it requires removing one or more of the inverter modules. If the ambi-
ent is high but no inverter is too hot there is no fault.
Possible causes:
• Ambient is too high.
• Cooling fan(s) not operating.
• Disrupted air flow.
• TS2, Ambient temperature sensor, shorted (very unlikely) or otherwise defective.
• Defective Relay board.
• Defective CCM.
• Defective Relay board.